Fix Shell Command

Replaces 'source' with '.' as the command 'source' is not
valid sh syntax.  It is only valid in bash, but the sg
command invokes sh, not bash.

BUG 717

Change-Id: I76f58120cff78420a751308c283798ad57b83df8
Signed-off-by: beierl <mbeierl@vmware.com>